In recent years, a so-called virtual machine (VM) is being used, which is a virtualization technique that allows a plurality of operating systems (OSs) to run on a single computer. For example, the virtualization technique is applied to servers to allow services hitherto provided by a plurality of servers running different OSs to be provided by a single server. Consequently, the cost of system construction and electric power consumption may be reduced as compared with the case of providing services by a plurality of servers.
The virtualization technique is also applied to client devices such as a personal computer (PC) to provide client behaviors corresponding to a plurality of people on a single PC. This enables a reduction in cost and electric power consumption as in the case of applying the virtualization technique to servers. In this way, the virtualization technique that enables a reduction in cost and electric power consumption is used in a variety of fields.
Japanese Laid-open Patent Publication No. 62-127790, Japanese Laid-open Patent Publication No. 2006-146756, and International Publication Pamphlet No. WO2007/111112 disclose related techniques.
However, in the related art, when the virtualization technique is applied to mobile terminals, switching of virtual machines becomes frequent, leading to poor user-friendliness.
Specifically, a typical mobile terminal displays each of states such as the remaining battery level, the radio wave intensity, and whether there are incoming emails or missed incoming calls in a part (hereinafter, referred to as a status notification area) of the screen. The typical mobile terminal alerts the user of a change in such a state by sound, vibration, or the like. The user having received this alert recognizes that there has been a change in state, checks the status notification area of the mobile terminal, and sees notification details as appropriate.
For example, suppose that a mobile terminal employing the virtualization technique is running an OS (A) and an OS (B) as virtual machines. When the OS (hereinafter, referred to as an accessible OS) on which the user is allowed to operate is the OS (A), the mobile terminal displays the screen of the OS (A) and does not display the screen of the OS (B). Accordingly, the mobile terminal alerts the user by using sound, vibration, or the like when the state of the OS (B) changes. The user having received this alert switches the accessible OS from the OS (A) to the OS (B), and then checks the alerted information. As an example, when the user receives an alert from the OS (B) while viewing a video image on the OS (A), the user has to go through a cumbersome operation of stopping playback of the video image once, switching the accessible OS to the OS (B), and then checking an overview of notification.